1. Field of the Invention
The present invention relates to a roulette game device. In particular, it relates to a roulette game device provided with a roulette wheel on which a ball revolving on the roulette wheel is easily viewed from game players and spectators around the roulette game device.
2. Related Art
The roulette game device is a game device in which a player buys or borrows a plurality of medals from a medal lending machine, a roulette game starts by inserting these medals into the roulette game device, and a predetermined number of medals are paid out if the player wins in a game.
The roulette game device performs a roulette game. More specifically, when a player selects a mark (number) located on the roulette wheel, the roulette wheels rotates, and a ball is thrown and revolves on the roulette wheel. At first, due to centrifugal force, the ball continues to revolve at a predetermined speed while pressing against an upper end portion of the outer circumferential wall, which is provided to protrude to inside from an upper end of the outer circumferential wall of the roulette wheel and made in a groove-shaped cross-section; however, when the centrifugal force weakens, the ball falls and is held in any of the pockets established at the lower side thereof due to gravity. These pockets correspond respectively to marks (numbers) disposed on the roulette wheel, and the mark (number) selected by a player is compared with a mark corresponding to the pocket in which the ball has fallen. In a case where a mark (number) selected by the player and the mark (number) of the pocket in which the ball has fallen match, it is determined that the player has won, and then medals are paid out to the player at a predetermined rate.
A player places a bet by predicting the mark corresponding to the pocket into which the ball will fall; however, this bet can be made even if the ball has been thrown onto the roulette wheel, and has started revolving. As a result, the player can place a bet by reading the trajectory on which the ball is rolling (e.g., see U.S. Pat. No. 4,869,505).
When a ball is thrown onto a roulette wheel, it is thrown along an outer circumferential wall of the roulette wheel with a certain degree of momentum, so that the ball revolves on the roulette wheel for a long time. When this is done, the ball thus thrown revolves along the outer circumferential wall for a while, due to the force applied when throwing and centrifugal force. Therefore, in the outer circumferential wall of the roulette wheel, it has been common for a large continuous flange to be provided at an upper end portion in an endless manner so as to cover a portion of an outer circumference of the roulette wheel toward inside thereof, so that an accommodating space of a toroidal shape made in a groove-shaped cross-section is formed entirely, while a distance between a lower side end portion and an upper side end portion of the outer circumferential wall is several times longer than a diameter of a ball.
In such a case, a case arises where the ball revolving on the roulette wheel is held in the accommodating space of a toroidal shape made in a groove-shaped cross-section, and for players surrounding the roulette game device, the ball revolving on a near side becomes unviewable. With such a problem, there becomes an important problem for a roulette game device in that a bet is made by predicting the trajectory on which the ball revolves, and relating this to the color and number of the pocket in which the ball will ultimately fall.
The present invention has an object of providing a roulette game device that allows the ball revolving on the roulette wheel to be easily viewed by players and spectators surrounding the roulette game device, and can facilitate betting for players.